| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1148695 | Tsagana | Dreaming (IOI13_dreaming) | C++20 | 0 ms | 0 KiB |
#include "dreaming.h"
#include <bits/stdc++.h>
#define lnl long long
#define pii pair<int, int>
#define pq priority_queue
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pp pop_back
#define F first
#define S second
using namespace std;
int P[10010], W[10010];
vector<pii> adj[10010];
pii dfs(int v, int p, int w)
{
P[v] = p;
W[v] = w;
pii ans = {0, v};
for (auto [u, w] : adj[v])
{
if (u == p) continue ;
pii tmp = dfs(u, v, w);
tmp.F += w;
ans = max(ans, tmp);
}
return ans;
}
int travelTime(int N, int M, int L, int V[], int U[], int T[])
{
for (int i = 0; i < M; i++)
{
adj[V[i]].pb({U[i], T[i]});
adj[U[i]].pb({V[i], T[i]});
}
fill(P, P+N, -2);
int ans = 0;
vector<int> v;
for (int i = 0; i < N; i++)
{
if (P[i] != -2) continue;
int s = dfs(i, -1, 0).S;
auto [x, u] = dfs(i, -1, 0);
int y = 0;
ans = max(ans, x);
int k = 2e9;
while (1)
{
k = min(k, max(x, y));
if (P[u] == -1) break;
y += W[u];
x -= W[u];
u = P[u];
}
v.pb(k);
}
sort(all(v));
reverse(all(v));
if (v.size() >= 2) ans = max(ans, L + v[0] + v[1]);
if (v.size() >= 3) ans = max(ans, L + L + v[1] + v[2]);
return ans;
}